BSD 4_3_Net_2 release

[unix-history] / usr / src / lib / libc / net / rcmd.3

diff --git a/usr/src/lib/libc/net/rcmd.3 b/usr/src/lib/libc/net/rcmd.3
index 942053f..44aa3d9 100644 (file)
--- a/usr/src/lib/libc/net/rcmd.3
+++ b/usr/src/lib/libc/net/rcmd.3
@@ -1,133 +1,188 @@
-.\" Copyright (c) 1983 Regents of the University of California.
-.\" All rights reserved.  The Berkeley software License Agreement
-.\" specifies the terms and conditions for redistribution.
+.\" Copyright (c) 1983, 1991 The Regents of the University of California.
+.\" All rights reserved.

 .\"
 .\"

-.\"    @(#)rcmd.3      6.4 (Berkeley) %G%
+.\" Redistribution and use in source and binary forms, with or without
+.\" modification, are permitted provided that the following conditions
+.\" are met:
+.\" 1. Redistributions of source code must retain the above copyright
+.\"    notice, this list of conditions and the following disclaimer.
+.\" 2. Redistributions in binary form must reproduce the above copyright
+.\"    notice, this list of conditions and the following disclaimer in the
+.\"    documentation and/or other materials provided with the distribution.
+.\" 3. All advertising materials mentioning features or use of this software
+.\"    must display the following acknowledgement:
+.\"    This product includes software developed by the University of
+.\"    California, Berkeley and its contributors.
+.\" 4. Neither the name of the University nor the names of its contributors
+.\"    may be used to endorse or promote products derived from this software
+.\"    without specific prior written permission.

 .\"
 .\"

-.TH RCMD 3X ""
-.UC 5
-.SH NAME
-rcmd, rresvport, ruserok \- routines for returning a stream to a remote command
-.SH SYNOPSIS
-.nf
-.PP
-.B "#include <sys/types.h>"
-.PP
-.B "rem = rcmd(ahost, inport, locuser, remuser, cmd, fd2p);"
-.B char **ahost;
-.B u_short inport;
-.B "char *locuser, *remuser, *cmd;"
-.B int *fd2p;
-.PP
-.B s = rresvport(port);
-.B int *port;
-.PP
-.B "ruserok(rhost, superuser, ruser, luser);"
-.B char *rhost;
-.B int superuser;
-.B char *ruser, *luser;
-.fi
-.SH DESCRIPTION
-.I Rcmd
-is a routine used by the super-user to execute a command on
+.\" THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
+.\" ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
+.\" IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
+.\" ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
+.\" FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
+.\" DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
+.\" OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
+.\" HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
+.\" LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
+.\" OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
+.\" SUCH DAMAGE.
+.\"
+.\"     @(#)rcmd.3     6.11 (Berkeley) 4/19/91
+.\"
+.Dd April 19, 1991
+.Dt RCMD 3
+.Os BSD 4.2
+.Sh NAME
+.Nm rcmd ,
+.Nm rresvport ,
+.Nm ruserok
+.Nd routines for returning a stream to a remote command
+.Sh SYNOPSIS
+.Fd #include <unistd.h>
+.Ft int
+.Fn rcmd "char **ahost" "int inport" "const char *locuser" "const char *remuser" "const char *cmd" "int *fd2p"
+.Ft int
+.Fn rresvport "int *port"
+.Ft int
+.Fn ruserok "const char *rhost" "int superuser" "const char *ruser" "const char *luser"
+.Sh DESCRIPTION
+The
+.Fn rcmd
+function
+is used by the super-user to execute a command on

 a remote machine using an authentication scheme based
 on reserved port numbers.
 a remote machine using an authentication scheme based
 on reserved port numbers.

-.I Rresvport
-is a routine which returns a descriptor to a socket
+The
+.Fn rresvport
+function
+returns a descriptor to a socket

 with an address in the privileged port space.
 with an address in the privileged port space.

-.I Ruserok
-is a routine used by servers
+The
+.Fn ruserok
+function
+is used by servers

 to authenticate clients requesting service with
 to authenticate clients requesting service with

-.IR rcmd .
+.Fn rcmd .

 All three functions are present in the same file and are used
 by the
 All three functions are present in the same file and are used
 by the

-.IR rshd (8C)
+.Xr rshd 8

 server (among others).
 server (among others).

-.PP
-.I Rcmd
+.Pp
+The
+.Fn rcmd
+function

 looks up the host
 looks up the host

-.I *ahost
+.Fa *ahost

 using
 using

-.IR gethostbyname (3N),
+.Xr gethostbyname 3 ,

 returning \-1 if the host does not exist.
 Otherwise
 returning \-1 if the host does not exist.
 Otherwise

-.I *ahost
+.Fa *ahost

 is set to the standard name of the host
 and a connection is established to a server
 residing at the well-known Internet port
 is set to the standard name of the host
 and a connection is established to a server
 residing at the well-known Internet port

-.IR inport .
-.PP
-If the call succeeds, a socket of type SOCK_STREAM
+.Fa inport .
+.Pp
+If the connection succeeds,
+a socket in the Internet domain of type
+.Dv SOCK_STREAM

 is returned to the caller, and given to the remote
 command as 
 is returned to the caller, and given to the remote
 command as 

-.B stdin
+.Em stdin

 and
 and

-.BR stdout .
+.Em stdout .

 If
 If

-.I fd2p
+.Fa fd2p

 is non-zero, then an auxiliary channel to a control
 process will be set up, and a descriptor for it will be placed
 in
 is non-zero, then an auxiliary channel to a control
 process will be set up, and a descriptor for it will be placed
 in

-.IR *fd2p .
+.Fa *fd2p .

 The control process will return diagnostic
 output from the command (unit 2) on this channel, and will also
 The control process will return diagnostic
 output from the command (unit 2) on this channel, and will also

-accept bytes on this channel as being UNIX signal numbers, to be
+accept bytes on this channel as being
+.Tn UNIX
+signal numbers, to be

 forwarded to the process group of the command.
 If
 forwarded to the process group of the command.
 If

-.I fd2p
+.Fa fd2p

 is 0, then the 
 is 0, then the 

-.B stderr
+.Em stderr

 (unit 2 of the remote
 command) will be made the same as the 
 (unit 2 of the remote
 command) will be made the same as the 

-.B stdout
+.Em stdout

 and no
 provision is made for sending arbitrary signals to the remote process,
 although you may be able to get its attention by using out-of-band data.
 and no
 provision is made for sending arbitrary signals to the remote process,
 although you may be able to get its attention by using out-of-band data.

-.PP
+.Pp

 The protocol is described in detail in
 The protocol is described in detail in

-.IR rshd (8C).
-.PP
+.Xr rshd 8 .
+.Pp

 The
 The

-.I rresvport
-routine is used to obtain a socket with a privileged
+.Fn rresvport
+function is used to obtain a socket with a privileged

 address bound to it.  This socket is suitable for use
 by 
 address bound to it.  This socket is suitable for use
 by 

-.I rcmd
-and several other routines.  Privileged addresses consist
-of a port in the range 0 to 1023.  Only the super-user
+.Fn rcmd
+and several other functions.  Privileged Internet ports are those
+in the range 0 to 1023.  Only the super-user

 is allowed to bind an address of this sort to a socket.
 is allowed to bind an address of this sort to a socket.

-.PP
-.I Ruserok
-takes a remote host's name, as returned by a
-.IR gethostent (3N)
-routine, two user names and a flag indicating if
-the local user's name is the super-user.  It then
-checks the file
-.I /etc/hosts.equiv
-and, possibly, 
-.I .rhosts
-in the current working directory (normally the local
-user's home directory) to see if the request for
-service is allowed.  A 0 is returned if the machine
-name is listed in the ``hosts.equiv'' file, or the
-host and remote user name are found in the ``.rhosts''
-file; otherwise 
-.I ruserok
-returns \-1.  If the
-.I superuser
-flag is 1, the checking of the ``host.equiv'' file is
-bypassed.
-.SH SEE ALSO
-rlogin(1C),
-rsh(1C),
-rexec(3X),
-rexecd(8C),
-rlogind(8C),
-rshd(8C)
-.SH BUGS
-There is no way to specify options to the
-.I socket
-call
-which
-.I rcmd
-makes.
+.Pp
+The
+.Fn ruserok
+argument
+takes a remote host's name, as returned by the
+.Xr gethostbyaddr 3
+routine, two user names and a flag indicating whether
+the local user's name is that of the super-user.  Then,
+if the user is
+.Em NOT
+the super-user, it checks the files
+.Pa /etc/hosts.equiv .
+If that lookup is not done, or is unsuccessful, the
+.Pa .rhosts
+in the local user's home directory is checked to see if the request for
+service is allowed.  If this file is owned by anyone other than the
+user or the super-user, or if it is writeable by anyone other than the
+owner, the check automatically fails.  A 0 is returned if the machine
+name is listed in the
+.Dq Pa hosts.equiv
+file, or the host and remote
+user name are found in the
+.Dq Pa .rhosts
+file; otherwise
+.Fn ruserok
+returns \-1.
+If the local domain (as obtained from
+.Xr gethostname 2 )
+is the same as the remote domain, only the machine name need be specified.
+.Sh DIAGNOSTICS
+The
+.Fn rcmd
+function
+returns a valid socket descriptor on success.
+It returns \-1 on error and prints a diagnostic message on the standard error.
+.Pp
+The
+.Fn rresvport
+function
+returns a valid, bound socket descriptor on success.
+It returns \-1 on error with the global value
+.Va errno
+set according to the reason for failure.
+The error code
+.Dv EAGAIN
+is overloaded to mean ``All network ports in use.''
+.Sh SEE ALSO
+.Xr rlogin 1 ,
+.Xr rsh 1 ,
+.Xr intro 2 ,
+.Xr rexec 3 ,
+.Xr rexecd 8 ,
+.Xr rlogind 8 ,
+.Xr rshd 8
+.Sh HISTORY
+These
+functions appeared in 
+.Bx 4.2 .